Mark Shea is Senior Content Editor of Catholic Exchange, and co-author of Catholic Scripture Study. He is the author of numerous best-selling books including Making Senses Out of Scripture, By What Authority?: An Evangelical Discovers Catholic Tradition and This is My Body: An Evangelical Discovers the Real Presence. Mark frequently appears on T.V. and radio, and is the beloved host of what may be the most popular Catholic blog on the Internet, Catholic and Enjoying It.